Here the Kronos keybed is upside down, showing the key hammers resting on a felt strip.

When the keyboard is right side up, the key hammers fall away from the felt, only hitting it when notes are struck.

Here you see where we've cut away the felt belonging to the problem 'E' key.

The felt was gouged away as if a screw or coin had been trapped there.

As a result, the key hammer traveled too far upward, striking the metal key frame and leaving the black mark you see in this photo.

We spliced in a similar piece of key felt to fix the damage and secured it with craft glue.

Next we reinstalled all the hammers, keys, and springs we'd taken out.

This video demonstrates Installing a White Key in a Korg Kronos or SV-1 keybed.

The black keys install in the same way, before the adjacent white keys.

This photo shows the little window in each key where you can see that the key spring is properly seated.

After reinstalling the keybed and the bottom cover, we looked at the Jordon Rudess Japanese Grand piano settings on the Kronos touch screen.